WO-A2-02/063723 discloses a plug with a housing, out of which housing various sets of pins can be slid, each set being intended for a specific type of power point. The pins are slid out by means of levers which extend outside through separate slots in the housing. The levers and the pins of one type are in each case connected to each other inside the housing by a connecting part which is slidably accommodated in the housing.
The plug furthermore has a safety element. Said safety element is accommodated so as to be slidable laterally in the housing. Slidable laterally should be understood as meaning in a direction transversely to the sliding directions of the pins. The safety element is slid by means of a push button located on the outside of the housing.
The safety element comprises various retaining bars. Said retaining bars extend in the same direction as the pins. The retaining bars have a sloping sliding surface which merges by way of a straight sliding surface, i.e. a surface extending in the direction of the pins, into an opening. The connecting part of the pins is provided with sliding lugs. During the process of sliding out a set of pins by means of the lever, the sliding lugs slide along the sloping sliding surfaces of the retaining bars. Owing to the fact that the pins are fixed in the radial direction, this sliding along the sloping sliding surfaces results in the safety element sliding sideways. At the end of the retaining bars the sliding lugs reach the position of the corresponding openings of the retaining bars. Under spring force the sliding lugs fall into the openings, so that the safety element slides back and the safety element is locked with the pins.
A disadvantage of the known plug is that said plug can become less reliable in the long term as a result of wear. The projecting corners of the sliding lug and the opening can become worn and acquire, for example, a chamfered or rounded profile. The result is that the locking of the sliding lug in the opening becomes less reliable and the pins can be inadvertently pushed into the housing.